Malicious PDF — malware analysis report

Static analysis result for SHA-256 21e8f04339bbc23f…

MALICIOUS

PDF

81.9 KB Created: 2021-05-28 15:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: 72ecc0e90c10e3c409fdea21ec00100b SHA-1: 4928c848cf33760f6fb04b9ce2366452163a0a7a SHA-256: 21e8f04339bbc23fd8efd50318605d1a00db6e988507e2513dde761d20bd9850
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The document body's text appears to be a deceptive lure related to financial accounting materials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://synerhu.ru/uplcv?utm_term=advanced+financial+accounting+10th+edition+ppt PDF link annotation
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/a3a757fc280e5bb24e226ebad60e857f/35262495592.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607adfae3740c---dudadajezopuvemuguzit.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/8ab3a601544700cf96bc47483c9fb60f/sakanulizapevowanoz.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16071736709621---diviferikezuxob.pdfIn PDF document text
    • https://africanresearchcenter.com/userfiles/file/98928415988.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/8fffb2f16c371233156da7de7167a943/ropig.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608a933481945---senidut.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/075707cc56b8b5a34af756d228962aa2/62483217342.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160948e60b933c---63973744881.pdfIn PDF document text
    • http://kasargod.net/uploads/file/62308183108.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078c682ddb26---gunapavixafola.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a00b5a14df8---gamixefusor.pdfIn PDF document text
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/e66a3226f483797dc3cb18d03813e895/46527037462.pdfIn PDF document text
    • https://aterhesseg.com/up_image/file/wodepalutujupubapakagiga.pdfIn PDF document text
    • http://bahtiyardishekimi.com/fckfiles/file/maxupalesaguwos.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fdfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFC 5384 bytes
SHA-256: f7a892d67d0ab299abaeda7da955771a5ca245cabb841c3f9a2000c3c155450c
font_01_sfnt_off0001105f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1105F 11936 bytes
SHA-256: 5afde73342d9a7305a5674d846ba954fb2388615d6884dd5cbebd8c4ab53b9d2